{"id":"nr-the-coding-agent-installed-on-a-developer-s-machine-is-now-an-attack-t-01ac6e","slug":"the-coding-agent-installed-on-a-developer-s-machine-is-now-an-attack-t-01ac6e","type":"raw_signal","title":"The coding agent installed on a developer's machine is now an attack target that must be inventoried and pinned","description":"Attackers are tampering with the agent clients themselves.","observed_at":"2026-10-31","record_date":"2026-10-31","date_kind":"observed_at","novelty":"notable","source_platform":"newruntime.com","topics":["claude","claude-code","codex"],"entities":["Symantec","Symantec Threat Hunter Team","OpenAI","Codex","Anthropic","Claude Code","Cursor","Cursor Extension Marketplace","Visual Studio Code","Microsoft"],"related_patterns":["agent-security-moves-to-runtime-boundaries","harness-architecture-outlives-model-choice","agent-ready-software-exposes-capabilities"],"source_url":"https://www.security.com/threat-intelligence/openai-claude-unauthorized-relays","source_urls":["https://www.security.com/threat-intelligence/openai-claude-unauthorized-relays","https://cursor.com/blog/claude-code-extension-security-notice","https://techcommunity.microsoft.com/blog/MicrosoftThreatProtectionBlog/now-generally-available-discover-local-ai-agents-with-microsoft-defender/4568216","https://github.blog/changelog/2026-10-13-enterprise-managed-settings-enforcement-updates","https://adversa.ai/agent-security-platform"],"why_it_matters":"Attackers are tampering with the agent clients themselves. A grey-market relay installs genuine Codex and Claude Code CLIs, then disables their sandboxes and reroutes their traffic, and a malicious Claude Code extension build reached up to 5,000 Cursor users. Defenders are responding at the client: Microsoft Defender now finds local agents and their MCP servers, and GitHub can require a minimum Copilot client version and fresh policy at startup.","verification_level":"source-linked","signal_type":"synthesis","synthesis_of":[{"slug":"symantec-grey-market-relay-installs-real-codex-and-d143b3","title":"Symantec: grey-market relay installs real Codex and Claude Code CLIs, then disables their sandboxes and reroutes traffic","url":"https://newruntime.com/posts/symantec-grey-market-relay-installs-real-codex-and-d143b3/"},{"slug":"malicious-claude-code-extension-v2-1-313-hit-d4c504","title":"Malicious Claude Code extension v2.1.313 hit Cursor's marketplace, exposing up to 5,000 developers.","url":"https://newruntime.com/posts/malicious-claude-code-extension-v2-1-313-hit-d4c504/"},{"slug":"microsoft-defender-discovery-of-local-ai-agents-and-b4e565","title":"Microsoft Defender discovery of local AI agents and their MCP servers is now generally available","url":"https://newruntime.com/posts/microsoft-defender-discovery-of-local-ai-agents-and-b4e565/"},{"slug":"github-lets-enterprises-force-fresh-copilot-policy-at-88951a","title":"GitHub lets enterprises force fresh Copilot policy at startup and enforce a minimum client version for the sandbox key","url":"https://newruntime.com/posts/github-lets-enterprises-force-fresh-copilot-policy-at-88951a/"},{"slug":"adversa-ai-launches-coding-agent-security-platform-for-282ec1","title":"Adversa AI launches Coding Agent Security Platform for Claude Code, Codex and agentic IDEs","url":"https://newruntime.com/posts/adversa-ai-launches-coding-agent-security-platform-for-282ec1/"}],"schema_version":"newruntime-agent-readable-v0.2","stable_id":"signal:the-coding-agent-installed-on-a-developer-s-machine-is-now-an-attack-t-01ac6e","retrieval_nugget":"Attackers are tampering with the agent clients themselves. A grey-market relay installs genuine Codex and Claude Code CLIs, then disables their sandboxes and reroutes their traffic, and a malicious Claude Code extension build reached up to 5,000 Cursor users.","status":"published","visuals":[],"editor":{"role":"editor","name":"Andrey Reshetnikov","profile":"https://newruntime.com/owner-profile.md","profile_json":"https://newruntime.com/owner-profile.json","same_as":["https://www.linkedin.com/in/reshetnikov1/","https://t.me/lapetuse"]},"routes":{"html":"https://newruntime.com/signals/the-coding-agent-installed-on-a-developer-s-machine-is-now-an-attack-t-01ac6e/","markdown":"https://newruntime.com/signals/the-coding-agent-installed-on-a-developer-s-machine-is-now-an-attack-t-01ac6e.md","json":"https://newruntime.com/signals/the-coding-agent-installed-on-a-developer-s-machine-is-now-an-attack-t-01ac6e.json"},"next_reads":[{"type":"topic","path":"/topics/claude/","url":"https://newruntime.com/topics/claude/","title":"Claude","reason":"Explore the claude topic hub.","media_type":"text/html","markdown_url":"https://newruntime.com/topics/claude.md","json_url":"https://newruntime.com/topics/claude.json"},{"type":"topic","path":"/topics/claude-code/","url":"https://newruntime.com/topics/claude-code/","title":"Claude Code","reason":"Explore the claude-code topic hub.","media_type":"text/html","markdown_url":"https://newruntime.com/topics/claude-code.md","json_url":"https://newruntime.com/topics/claude-code.json"},{"type":"topic","path":"/topics/codex/","url":"https://newruntime.com/topics/codex/","title":"Codex","reason":"Explore the codex topic hub.","media_type":"text/html","markdown_url":"https://newruntime.com/topics/codex.md","json_url":"https://newruntime.com/topics/codex.json"},{"type":"collection","path":"/signals/","url":"https://newruntime.com/signals/","title":"Raw Signals","reason":"Open every source-linked raw signal.","media_type":"text/html","json_url":"https://newruntime.com/signals.json"},{"type":"collection","path":"/source-ledger.json","url":"https://newruntime.com/source-ledger.json","title":"Source Ledger","reason":"Inspect the public source evidence graph.","media_type":"application/json"}]}